1. Field of the Invention
The present invention discloses a method and composition for the treatment of bacterial infections by the parenteral introduction of a lysing enzyme blended with an appropriate carrier into a patient. The injection can be done intramuscularly, subcutaneously, or intravenously.
2. Description of the Prior Art
In the past, antibiotics have been used to treat various infections. The work of Selman Waksman in the introduction and production of Streptomycetes, and Dr. Fleming's discovery of penicillin, as well as the work of numerous others in the field of antibiotics, are well known. Over the years, there have been additions and chemical modifications to the “basic” antibiotics in attempts to make them more powerful, or to treat people allergic to these antibiotics.
Others have found new uses for these antibiotics. U.S. Pat. No. 5,260,292 (Robinson et al.) discloses the topical treatment of acne with aminopenicillins. The method and composition for topically treating acne and acneiform dermal disorders includes applying an amount of an antibiotic, effective for treating acne and acneiform dermal disorders, selected from the group consisting of ampicillin, amoxicillin, other aminopenicillins, and cephalosporins, and derivatives and analogs thereof. U.S. Pat. No. 5,409,917 (Robinson et al.) discloses the topical treatment of acne with cephalosporins.
However, as more antibiotics have been prescribed or used at an ever increasing rate for a variety of illnesses, increasing numbers of bacteria have developed a resistance to antibiotics. Larger doses of stronger antibiotics are now being used to treat ever more resistant strains of bacteria. Consequently, multiple antibiotic resistant bacteria have been developed. The use of more antibiotics and the number of bacteria showing resistance has led to increases in the amount of time that the antibiotics need to be used. Broad, non-specific antibiotics, some of which have detrimental effects on the patient, are now being used more frequently. Additionally, the number of people showing allergic reactions to antibiotics appears to be increasing.
Consequently, other efforts have been sought to first identify and then kill bacteria.
Attempts have been made to treat bacterial diseases with by the use of bacteriophages. U.S. Pat. No. 5,688,501 (Merril, et al.) discloses a method for treating an infectious bacterial disease with lytic or non-lytic bacteriophages that are specific for particular bacteria.
U.S. Pat. No. 4,957,686 (Norris) discloses a procedure of improved dental hygiene which comprises introducing into the mouth bacteriophages parasitic to bacteria which possess the property of readily adhering to the salivary pellicle.
It is to be noted that the direct introduction of bacteriophages into an animal to prevent or fight diseases has certain drawbacks. Specifically, the bacteria must be in the right growth phase for the phage to attach. Both the bacteria and the phage have to be in the correct and synchronized growth cycles. Additionally, there must be the right number of phages to attach to the bacteria; if there are too many or too few phages, there will either be no attachment or no production of the lysing enzyme. The phage must also be active enough. The phages are also inhibited by many things including bacterial debris from the organism the phages are going to attack. Further complicating the direct use of bacteriophage is the possibility of immunological reactions, rendering the phage non-functional.
Consequently, others have explored the use of other safer and more effective means to treat and prevent bacterial infections.
One bacteria for which a more effective treatment has been extensively explored is Streptococcus. The genus Streptococcus is comprised of a wide variety of both pathogenic and commensal gram-positive bacteria which are found to inhabit a wide range of hosts, including humans, horses, pigs, and cows. Within the host, streptococci are often found to colonize the mucosa surfaces of the mouth, nares and pharynx. However, in certain circumstances, they may also inhabit the skin, heart or muscle tissue.
Pathogenic streptococci of man include S. pyogenes, S. pneumoniae, and S. faecalis. While Group A streptococci may be present in the throat or on the skin and cause no symptoms of disease, they may also cause infections that range from mild to severe, and even life-threatening. Among the pathogenic hemolytic streptococci, S. pyogenes, or group A streptococci have been implicated as the etiologic agent of acute pharyngitis (“strep throat”), impetigo, rheumatic fever, scarlet fever, glomerulonephritis, and invasive fasciitis. Necrotizing fasciitis (sometimes described by the media as “the flesh-eating bacteria”) is a destructive infection of muscle and fat tissue. Invasive group A streptococcal infections occur when the bacteria get past the defenses of the person who is infected. About 10,000–15,000 cases of invasive GAS disease occur in the United States each year, resulting in over 2,000 deaths. CDC estimates that 500 to 1,500 cases of necrotizing fasciitis and 2,000 to 3,000 cases of streptococcal toxic shock syndrome occur each year in the United States. Approximately 20% of patients with necrotizing fasciitis die, and 60% of patients with streptococcal toxic shock syndrome die. About 10 to 15% of patients with other forms of invasive group A streptococcal disease die.
Additionally, Group C Streptococcus can cause cellulitis from skin breaks, although cellulitis is normally associated with Staphylococcus aureus. Cellulitis can result in death, particularly in older individuals or in individuals who are already weakened.
Reports have described the characteristics of an enzyme produced by the group C streptococcal organism after being infected with a particular bacteriophage identified as C1 (Maxted, W. R. “The Active Agent in Nascent Page Lywsis of Streptococci,” J. Gen Micro., vol 16, pp 585–595, 1957, Krause, R. M., “Studies on the Bacteriophages of Hemolytic Streptococci,” J. Exp. Med, vol. 108, pp 803–821, 1958) and Fischetti, (Fischetti, V. A., et al, “Purification and Physical Properties of Group C Streptococcal Phage Associated Lysin,” J. Exp. Med, Vol 133 pp. 1105–1117, 1971). The enzyme was given the name lysin and was found to specifically cleave the cell wall of group A, group C, and group E streptococci. These investigators provided information on the characteristics and activities of this enzyme with regard to lysing the group A streptococci and releasing the cell wall carbohydrate.
U.S. Pat. No. (application Ser. No. 08/962,523)(Fischetti, et. al.) and U.S. Pat. No. (application Ser. No. 09/257,026)(Fischetti et al.) disclose the use of an oral delivery mode, such as a candy, chewing gum, lozenge, troche, tablet, a powder, an aerosol, a liquid or a liquid spray, containing a lysin enzyme produced by group C streptococcal bacteria infected with a C1 bacteriophage for the prophylactic and therapeutic treatment of Streptococcal A throat infections, commonly known as strep throat.
U.S. Pat. No. 6,056,954 Fischetti and Loomis discloses a method for the prophylactic and therapeutic treatment of bacterial infections, which comprises the treatment of an individual with an effective amount of a lytic enzyme composition specific for the infecting bacteria, and a carrier for delivering said lytic enzyme. The methods disclosed included the topical, oral, and respiratory methods of delivering the enzyme. Another method disclosed in that application includes the use of suppositories. These methods and compositions can be used for the treatment of upper respiratory infections, skin infections, wounds and burns, vaginal infections, eye infections, intestinal disorders, and dental problems.
U.S. Pat. No. 6,056,955 (Fischetti and Loomis) discloses a method and composition for the topical treatment of streptococcal infections by the use of a lysin enzyme blended with a pharmaceutically acceptable carrier suitable for topical application to dermal tissues. The method for the treatment of dermatological streptococcal infections comprises administering a composition comprising effective amount of a therapeutic agent, with the therapeutic agent comprising a lysin enzyme produced by group C streptococcal bacteria infected with a C1 bacteriophage. The therapeutic agent can be in a pharmaceutically acceptable carrier.
The use of phage associated lytic enzymes produced by the infection of a bacteria with a bacteria specific phage has numerous advantages for the treatment of diseases. As the phage are targeted for specific bacteria, the lytic enzymes do not interfere with normal flora. Also, lytic phages primarily attack cell wall structures which are not affected by plasmid variation. The actions of the lytic enzymes are fast and do not depend on bacterial growth.
However, sometimes the bacterial infections, by the time they are treated, have developed into more serious illnesses. For example, dermatological infections such as Staphylococcus aureus and Streptococcal pneumoniae can develop into cellulitis, which, unchecked, can lead to a degradation of the connective tissue, septicemia, and possibly death. Other bacterial infections can also evolve into deep tissue infections. Other infections by other bacteria, not necessarily dermatological by nature, can infect and localize in certain tissues of the body, making the infections difficult to treat.